Influenza can have an important impact on cardiovascular well-being. According to research published in the New England Journal of Medicine, in the first seven days after a laboratory confirmed diagnosis of influenza, the probability of onset of myocardial infarction increased six times. The study – as Dr. Maddalena Lettino of the cardiovascular Department of Humanitas explains – provides relevant information about the role of inflammation in the process leading to heart disease and supports the usefulness of adherence to the seasonal vaccination campaign by older people.
Older people most at risk
Researchers at the Institute for Clinical Evaluative Sciences and Public Health Ontario (Canada) analyzed data for nearly twenty thousand adults affected by influenza, confirmed by laboratory tests, between 2009 and 2014 and identified 322 patients who were hospitalized for heart attack within the first year of influenza diagnosis. At the end of the research, this increased risk of heart attack emerged in the first seven days of influenza infection.
It has been seen that the risk, the researchers add, was greater for the elderly, for those who had been affected by type B influenza and for patients who had suffered the first heart attack. Other infections caused by several respiratory viruses, although to a lesser degree than influenza, have also been associated with an increased risk of heart attack.
Inflammation is the element that can explain this increased risk of heart attack: “Following infection in the body, a generalized inflammation is triggered, which can contribute to the instability of atherosclerotic plaques and promote an episode of coronary thrombosis,” says Dr. Lettino. For this to happen, there must be a certain propensity of the subject to go through a major cardiovascular event, so there must be an unknown coronary heart disease. That’s why the risk was higher in the first episode of a heart attack, only apparently healthy “.
As seen, it was older people who presented a higher risk of post-influenza infarction: “After the age of 65 years, more than one cardiovascular risk factor may presumably be present and the chances of a coronary event are not insignificant. For these subjects, therefore, a state of systemic inflammation can be a triggering factor of an underlying coronary artery disease that becomes unstable,” adds Dr. Lettino.
Support for vaccination
The data, remember the researchers, together with those from previous research on influenza vaccination that have proved to be able to reduce cardiovascular events and mortality, confirm the usefulness of this form of prevention.
In Italy, every year, influenza vaccinations are indicated in a time window that tends to run from mid-October to the end of December. Vaccination is an effective and safe tool against the influenza virus and to prevent its complications. In particular, the indication to protect oneself with the vaccine is valid, among others, for those who are at least sixty-five years old, those with diseases that increase the risk of complications, including cardiovascular pathologies.
All international guidelines recommend flu vaccination “and this study adds further motivation to the need to practice flu vaccine in individuals over 65 years of age. Since seasonal influenza affects a large number of individuals, this correlation with increased cardiovascular risk is no more than an additional reason for adhering to vaccination campaigns,” the specialist concludes.